The segmental precast adhesive assembly bridge construction technology has been developed quite maturely. The prestressed concrete simply supported beams and continuous beam bridge types with adhesive joint construction technology have been widely adopted in expressways, high-speed railways, and urban rail transit, and has become the main construction methods for segmental assembled bridges. This article will introduce its main features to you.

Process Principle

The entire continuous box girder is longitudinally divided into several segments. The segments are prefabricated in a matching manner using the long and short line combination method in the beam factory. After the age of the segmental concrete reaches the design requirements, they are hoisted into the interior of the bridge builder. Relying on the support of the lifting beam on the bridge builder, they are placed and adjusted in position in a certain order, glued and temporarily tensioned. Then, the steel strands are threaded, tensioned, and grouted, and the box girders are erected span by span and section by section.

Scope of Application

This construction method is applicable to the construction of prestressed concrete continuous box girders, simply supported then continuous bridges, and continuous rigid frames.

Features of the Construction Method

This construction method has the following features:

1. Breaking the whole into parts, with high product quality. The entire continuous beam is divided into several segments, all of which are prefabricated in a factory-style beam factory. The quality of the concrete is easy to ensure, and the appearance quality of the entire span of the beam is good.

2.High precision in alignment control. By using the alignment control system for the matching prefabrication of continuous beams and the measurement control and positioning system for the installation and anchoring of the 0# segment at the pier top, the precision control of segmental prefabrication is within 2mm, and the measurement precision of the 0# segment can be controlled within 1mm, ensuring that the overall alignment of the completed bridge meets the design requirements. At the same time, the segment has a long curing time and a late loading age, resulting in small creep camber of the beam body and long-term loss of prestress after the bridge is completed, and the alignment of the beam body is easy to control.

3. Shortening the construction period. The segmental prefabrication of the upper part of the bridge and the construction of the lower bearing platform and pier columns can be carried out simultaneously. Using the flow method of operation, segmental prefabrication and installation can be carried out separately without interfering with each other, shortening the construction period.

4. Sealing of the duct, with strong reliability. A prestressed duct connection device for segmental adhesive assembled beams with excellent sealing performance has been developed, solving the problem of water and grout leakage at the connection of the prestressed ducts, and ensuring the construction quality of the prestressed ducts at the joints of the segmental beams.

5. Closure by hanger, with convenient operation. The closure by hanger reduces the counterweight compared with the traditional suspended basket closure, avoids the secondary internal force caused by external forces during the closure of the double T structures, making the internal force of the completed bridge more reasonable, and has a low cost, low construction difficulty, and low construction risk.

6. Wide scope of application. It is not restricted by geographical conditions and is not affected by seasons. During the segmental adhesive assembly and erection, regardless of the height of the piers, the quality of the geographical conditions, the presence of rivers and valleys, or the crossing of seas and rivers, the construction is not affected. The box girder is prefabricated in advance and assembled in winter without the need to take winter construction measures, and the quality is guaranteed.

7. Green and environmentally friendly. Compared with the cantilever casting and cast-in-place beams, the segmental assembly has a smaller construction footprint, less concrete work, reduces sewage discharge, waste, noise pollution, etc. The construction does not require the erection of ground supports, is not restricted by the terrain, and causes little damage to the natural environment around the bridge site. In the bridge construction across roads, railways, canals, etc., it reduces dewatering and traffic closures, reduces the impact on the surrounding communities, and is conducive to the construction of ecological civilization.